US5042376A - Aerodynamic damper for an impact printing actuator - Google Patents

Aerodynamic damper for an impact printing actuator Download PDF

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Publication number
US5042376A
US5042376A US07/230,624 US23062488A US5042376A US 5042376 A US5042376 A US 5042376A US 23062488 A US23062488 A US 23062488A US 5042376 A US5042376 A US 5042376A
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US
United States
Prior art keywords
flat surface
recess
armature
aerodynamic
damper
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US07/230,624
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English (en)
Inventor
Carlo Fare
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bull HN Information Systems Italia SpA
Original Assignee
Bull HN Information Systems Italia SpA
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Filing date
Publication date
Application filed by Bull HN Information Systems Italia SpA filed Critical Bull HN Information Systems Italia SpA
Assigned to HONEYWELL BULL ITALIA S.P.A., CALUSO, ITALY A CORP. OF REP. OF ITALY reassignment HONEYWELL BULL ITALIA S.P.A., CALUSO, ITALY A CORP. OF REP. OF ITALY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: FARE, CARLO
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
    • B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
    • B41J2/27—Actuators for print wires
    • B41J2/28—Actuators for print wires of spring charge type, i.e. with mechanical power under electro-magnetic control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J9/00—Hammer-impression mechanisms
    • B41J9/42—Hammer-impression mechanisms with anti-rebound arrangements

Definitions

  • the present invention relates to an aerodynamic damper for an impact printing actuator.
  • the printing actuators used in high speed printers for data processing systems and particularly in dot matrix printers consist of electromagnets where the actuation of a movable armature causes the printing operation.
  • actuators and two operative modes Two kinds of actuators and two operative modes can be distinguished; that is, actuators provided with a simple electromagnetic and actuators provided with a permanent magnet, as well as actuators operating by armature attraction and actuators operating by armature release.
  • the movable armature In actuators of the simple electromagnet type, operating in attraction mode, the movable armature, in rest position, is spaced apart from a magnetic pole and rests on a stop element.
  • An air gap is present between the armature and the magnetic pole.
  • the electromagnet energization causes the armature to be attracted against the magnetic pole and the deenergization causes the release and the return of the armature, imposed by resilient means, to the rest position.
  • the movable armature In actuators of the simple electromagnet type, operating in release mode, the movable armature is, in rest condition, attracted against a magnetic pole, owing to the electromagnet energization.
  • the deenergization of the electromagnet causes the release of the armature, owing to resilient means and the consequent print operation, while the energization cuases the armature attraction in the rest position.
  • the movable armature In the permanent magnet type actuators, which generally operate in release mode only, the movable armature, when at rest, is attracted against a magnetic pole.
  • the electromagnet energization causes the neutralization of the magnetic field produced by the permanent magnet and the consequent release of the armature.
  • the deenergization of the electromagnet causes the armature to be pulled against the magnetic pole.
  • dampers of various types have been used, such as resilient, ballistic, and pneumatic dampers.
  • a stop element is provided which defines a flat surface against which a corresponding flat surface of the armature lays down.
  • a compressed air cushion is formed between the two surfaces. This cushion performs a braking action on the moving armature, and dampens its impact against the rest surface, reducing the rebound.
  • FIG. 1 shows in section a preferred form of printing actuator embedding the aerodynamic damper of the invention
  • FIG. 2 shows in section the shape of the aerodynamic damper of the invention
  • FIG. 3 shows in section an alternative shape of the aerodynamic damper of the invention
  • FIG. 4 shows in qualitative form the local pressure distribution caused by the aerodynamic damper of the invention compared with the one caused by a conventional damping device.
  • FIG. 1 shows in section a preferred form of embodiment of printing actuator embodying the aerodynamic damper of the invention.
  • the actuator comprises a first magnetic yoke 1, a cylindrical magnetic column 2, onto which a winding 3 is inserted, a magnetic column 4 consisting of a permanent magnet, a second magnetic yoke 5, directing the magnetic flux to column 2, a magnetic spacer 6, and a resilient magnetic armature 7 cantilever mounted on spacer 6 and extending towards magnetic column 2.
  • Armature 7 is provided with a cylindrical post 8 for reclosure of the magnetic circuit, the post facing the pole end of magnetic column 2 and being coaxial thereto.
  • Post 8 inserts in an opening of yoke 5 and faces with a flat surface 9 the upper face 10 of pole 2.
  • the armature 7 is elastically bent and attracted towards column 2 and surface 9 is in contact with the upper face 10 of column 2.
  • Armature 7 supports, at its free end, an actuation arm 11 to which a printing needle 12 is fixed.
  • Such recess has for instance the shape of a spherical segment having a depth (height) on the order of 30-60 micron and diameter on the order of 3-4 mm.
  • the flat surface stopping the armature in rest position, and formed by the upper surface 10 of pole 2 has a recess 13, drawn in the pole and having peripheral walls 14, 15 slanted relative to the flat surface 10.
  • the recess 13, as shown in FIG. 3, may have a frusto-conical shape having a depth (height) on the order of 30-60 microns and maximum diameter on the order of 3-4 mm.
  • the pressure at the border is obviously equal to the ambient pressure and has a peak at the surface center.
  • the recess may be located as well in the movable armature, as well as in the stop element, or both.
  • the suggested sizing is largely susceptible of change depending on the size of the armature and stop surface, it being clear that in the case the recess affects a section of the magnetic circuit, it is advisable that the depth of the recess be limited to the order of few hundredths of a millimeter so as not to cause substantive non-uniformity in the distribution of the magnetic flux.

Landscapes

  • Impact Printers (AREA)
  • Electromagnets (AREA)
US07/230,624 1987-09-02 1988-08-10 Aerodynamic damper for an impact printing actuator Expired - Lifetime US5042376A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT8721782A IT8721782A0 (it) 1987-09-02 1987-09-02 Smorzatore aerodinamico per attuatore di stampa.
IT21782A/87 1987-09-02

Publications (1)

Publication Number Publication Date
US5042376A true US5042376A (en) 1991-08-27

Family

ID=11186774

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/230,624 Expired - Lifetime US5042376A (en) 1987-09-02 1988-08-10 Aerodynamic damper for an impact printing actuator

Country Status (4)

Country Link
US (1) US5042376A (fr)
EP (1) EP0305916B1 (fr)
DE (1) DE3873221T2 (fr)
IT (1) IT8721782A0 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02215543A (ja) * 1989-02-16 1990-08-28 Seiko Epson Corp インパクトドットヘッド

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3504623A (en) * 1968-04-03 1970-04-07 Itt Hammer arrangement for high-speed printers
US3941052A (en) * 1974-04-29 1976-03-02 Shugart Associates, Inc. Print hammer apparatus with angularly disposed mating hammer and pole faces to prevent contact bounce
JPS559883A (en) * 1978-07-08 1980-01-24 Citizen Watch Co Ltd Printing mechanism in printer
US4308794A (en) * 1978-07-13 1982-01-05 Contardo Adamoli Hammer assembly for a serial typing device
US4388861A (en) * 1980-09-19 1983-06-21 International Business Machines Corporation Bank for accommodating several print hammer units
US4529326A (en) * 1981-01-19 1985-07-16 Facit Aktiebolag Print hammer for printers and typewriters
JPS61193867A (ja) * 1985-02-22 1986-08-28 Nec Corp 印字ハンマ
JPS6230056A (ja) * 1985-08-01 1987-02-09 Nhk Spring Co Ltd プリンタヘツド用緩衝材
JPS6299170A (ja) * 1985-10-25 1987-05-08 Matsushita Electric Works Ltd ハンマ−ソレノイド
JPS62124960A (ja) * 1985-11-27 1987-06-06 Hiroshi Kaneko プリンタヘツド用緩衝材
US4900169A (en) * 1985-06-28 1990-02-13 Ing. C. Olivetti & C., S.P.A. Print hammer damping mechanism for typewriters and like printing machines

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE404898B (sv) * 1976-10-11 1978-11-06 Facit Ab Anordning for punktformig paverkan av ett informationsberande medium
EP0237600B1 (fr) * 1986-03-19 1991-01-16 Ibm Deutschland Gmbh Butée d'amortissement élastique pour actionneur de marteau d'impression dans une imprimante à impact

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3504623A (en) * 1968-04-03 1970-04-07 Itt Hammer arrangement for high-speed printers
US3941052A (en) * 1974-04-29 1976-03-02 Shugart Associates, Inc. Print hammer apparatus with angularly disposed mating hammer and pole faces to prevent contact bounce
JPS559883A (en) * 1978-07-08 1980-01-24 Citizen Watch Co Ltd Printing mechanism in printer
US4308794A (en) * 1978-07-13 1982-01-05 Contardo Adamoli Hammer assembly for a serial typing device
US4388861A (en) * 1980-09-19 1983-06-21 International Business Machines Corporation Bank for accommodating several print hammer units
US4529326A (en) * 1981-01-19 1985-07-16 Facit Aktiebolag Print hammer for printers and typewriters
JPS61193867A (ja) * 1985-02-22 1986-08-28 Nec Corp 印字ハンマ
US4900169A (en) * 1985-06-28 1990-02-13 Ing. C. Olivetti & C., S.P.A. Print hammer damping mechanism for typewriters and like printing machines
JPS6230056A (ja) * 1985-08-01 1987-02-09 Nhk Spring Co Ltd プリンタヘツド用緩衝材
JPS6299170A (ja) * 1985-10-25 1987-05-08 Matsushita Electric Works Ltd ハンマ−ソレノイド
JPS62124960A (ja) * 1985-11-27 1987-06-06 Hiroshi Kaneko プリンタヘツド用緩衝材

Also Published As

Publication number Publication date
DE3873221D1 (de) 1992-09-03
EP0305916A3 (en) 1989-09-06
EP0305916A2 (fr) 1989-03-08
DE3873221T2 (de) 1993-02-18
IT8721782A0 (it) 1987-09-02
EP0305916B1 (fr) 1992-07-29

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